1. Field of the Invention
The present invention relates to straddle vehicles such as a motorcycle, an electric two-wheeled vehicle, or an automated three-wheeled vehicle. Particularly, the present invention relates to a straddle vehicle having a structure for preventing entry of foreign matters into a head pipe.
2. Description of the Related Art
Japanese Examined Utility Model Application Publication No. Hei. 6-37034 discloses an exemplary steering device of a straddle vehicle. This steering device includes a steering stem coupled to a handle and inserted into a cylindrical head pipe. The steering stem is supported by the head pipe and is rotatable together with the handle.
The head pipe has a bearing retaining section for retaining a bearing at an end portion thereof. The steering stem is rotatably supported by the bearing. A nut is threadingly engaged with a portion of an outer periphery of the steering stem which is located above the head pipe. After the steering stem is inserted into the head pipe retaining the bearing, the nut is rotated and displaced in a downward direction. Thus, the bearing is pressed against the bearing retaining section and fastened to the head pipe. In addition, the head pipe is provided at an end portion thereof with a cover member having a sealing capability to prevent water, dust and other material from entering inside of the head pipe.
In this steering device, an inner peripheral portion of the cover member is sandwiched between an upper surface of the bearing and a lower surface of a steering nut. The cover member covers an opening of the head pipe. The cover member is provided at an outer peripheral portion thereof with a seal retaining section protruding downward in a location which is radially outward relative to an outer peripheral surface of the head pipe. A seal member is mounted to an inner peripheral surface of the seal retaining section. A lip of the seal member is sealingly attached to the outer peripheral surface of the head pipe.
In this configuration, to enable the seal member to appropriately perform a sealing function, it is necessary to control a distance from the outer peripheral surface of the head pipe to the seal retaining section. To this end, the outer peripheral surface of the head pipe is required to be processed, which may make manufacturing steps of the head pipe complicated. If an upper end portion of the head pipe, which is easily visible from a driver straddling the vehicle, is covered with the cover member, an external appearance of the steering device may be impaired.